Skip to main content

THE LIVING CELL

The word cell, comes from the latin word, 'cellula' meaning a small room or a monk's tiny bare room. This descriptive name, was chosen by an English scientist Robert Hooke in the book he published in 1665, after he examined microscopically, cork tissue (a plant material) and saw that they contain neatly arranged little chambers. He compared this chambers to the room monk's lived in and he called them cells.

In 1835, a french microscopic zoologist Felix Dujardin, examined a thin slice of animal tissue under much improved microscope and discovered that the cells have content (jelly like material). He named the cntent sarcode. In the same year, Czech experimental physiologist,  Johannes Evangelista Purkinje observed the presence of small granules while looking at the plant tissue through a microscope. Later in 1839, Purkinje named the content, protoplasm, Hugo Von Mohl a German botanist also in 1846 named it protoplasm.

In 1838, Mathias Jakob  Schleiden, a german botanist carried out an extensive study on the structure of plants and concluded that plants were composed of cells.

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism, that is classified as living and is often called the building block of life. Some organisms are unicellular eg bacteria, amoeba, paramecium, chlamydomonas. Others are multicellular eg hydra, earthworms, birds, elephant, man etc. (Humans are estimated to have 100 trillion cells) cells consist of protein rich material that is differentiated into cytoplasm and a nucleus forming the protoplasm, which consists of organised complex materials.



This excerpts is from my book, A glance at cell biology. This book can be bought from the online store, www.morebooks.de (https://www.morebooks.de/gb/search?utf8=%E2%9C%93&q=Ukponmwan+ifueko+oghogho+)

or

Comments

Popular posts from this blog

problem of plant living in fresh water habitat

Buoyancy The density of fresh water is considerably less than that of the sea and such floatation is a greater problem for fresh water plankton. There is occasional flooding which submerges the plants.  The water lilies, water lettuce, water hyacinth are able to stay afloat because of the air spaces in the lower part of the leaves as well as in the skins and roots.

Processing of animal products

Alot of products are derived from livestock, both edible and inedible, for this discourse, we look at the edible products. The edible products include,  milk, meat eggs. Milk processing Milk is the lacteal secretion from the mammary gland of females livestock. Although in modern days, milk can also be gotten from plants eg soybean milk, coconut milk. The milk from animals from cow, goat, buffallo etc. The milk is a very good vehicle for transmission of pathogens so milk handlers should exercise the utmost level of personal hygiene, the milk processing area should be sanitized. The milk handlers must be free from gastro-intestinal infections, no coughing, sneezing, diarrhoea etc. Note that the dairy animals are kept in hygienic condition, sick or animals receiving treatment should not be milk. The udders should be washed prior to milking in order to reduce the risk of contamination of the milk. Once milk is collected from the animals through a milking machine, the t...

The Nucleic Acids

These are molecules that are essential to and characteristic of life on earth. They form the genetic material of all living organisms including the simplest virus. These compunds are found mainly in the nucleus.  They are DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid). Nucleic acids have the same basic structure  in all organisms.  Excerpts from the book a glance at cell biology by Ukponmwan Ifueko Oghogho Available @  https://www.morebooks.de/gb/search?utf8=%E2%9C%93&q=Ukponmwan+ifueko+oghogho+ amazon.com/author/ifuekoukponmwan